"use strict";

// Do this as the first thing so that any code reading it knows the right env.
process.env.BABEL_ENV = "production";
process.env.NODE_ENV = "production";
process.env.GENERATE_SOURCEMAP = "false";
// Makes the script crash on unhandled rejections instead of silently
// ignoring them. In the future, promise rejections that are not handled will
// terminate the Node.js process with a non-zero exit code.
process.on("unhandledRejection", (err) => {
	throw err;
});

// Ensure environment variables are read.
require("../config/env");

const path = require("path");
const chalk = require("react-dev-utils/chalk");
const fs = require("fs-extra");
const bfj = require("bfj");
const webpack = require("webpack");
const configFactory = require("../config/webpack.config");
const paths = require("../config/paths");
const checkRequiredFiles = require("react-dev-utils/checkRequiredFiles");
const formatWebpackMessages = require("react-dev-utils/formatWebpackMessages");
const printHostingInstructions = require("react-dev-utils/printHostingInstructions");
const FileSizeReporter = require("react-dev-utils/FileSizeReporter");
const printBuildError = require("react-dev-utils/printBuildError");

const measureFileSizesBeforeBuild =
	FileSizeReporter.measureFileSizesBeforeBuild;
const printFileSizesAfterBuild = FileSizeReporter.printFileSizesAfterBuild;
const useYarn = fs.existsSync(paths.yarnLockFile);

// These sizes are pretty large. We'll warn for bundles exceeding them.
const WARN_AFTER_BUNDLE_GZIP_SIZE = 512 * 1024;
const WARN_AFTER_CHUNK_GZIP_SIZE = 1024 * 1024;

const isInteractive = process.stdout.isTTY;

// Warn and crash if required files are missing
if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
	process.exit(1);
}

const argv = process.argv.slice(2);
const writeStatsJson = argv.indexOf("--stats") !== -1;

// Generate configuration
const config = configFactory("production");

// We require that you explicitly set browsers and do not fall back to
// browserslist defaults.
const { checkBrowsers } = require("react-dev-utils/browsersHelper");
checkBrowsers(paths.appPath, isInteractive)
	.then(() => {
		// First, read the current file sizes in build directory.
		// This lets us display how much they changed later.
		return measureFileSizesBeforeBuild(paths.appBuild);
	})
	.then((previousFileSizes) => {
		// Remove all content but keep the directory so that
		// if you're in it, you don't end up in Trash
		fs.emptyDirSync(paths.appBuild);
		// Merge with the public folder
		copyPublicFolder();
		// Start the webpack build
		return build(previousFileSizes);
	})
	.then(
		({ stats, previousFileSizes, warnings }) => {
			if (warnings.length) {
				console.log(chalk.yellow("编译过程中发生的警告.\n"));
				console.log(warnings.join("\n\n"));
				console.log(
					"\nSearch for the " +
						chalk.underline(chalk.yellow("keywords")) +
						" to learn more about each warning."
				);
				console.log(
					"可以在语句报错的地方之前加上" +
						chalk.cyan("// eslint-disable-next-line") +
						" 这条命令行.\n"
				);
			} else {
				console.log(chalk.green("成功完成编译打包.\n"));
			}

			console.log("在gzip压缩之后生成的文件:\n");
			printFileSizesAfterBuild(
				stats,
				previousFileSizes,
				paths.appBuild,
				WARN_AFTER_BUNDLE_GZIP_SIZE,
				WARN_AFTER_CHUNK_GZIP_SIZE
			);
			console.log();

			const appPackage = require(paths.appPackageJson);
			const publicUrl = paths.publicUrlOrPath;
			const publicPath = config.output.publicPath;
			const buildFolder = path.relative(process.cwd(), paths.appBuild);
			printHostingInstructions(
				appPackage,
				publicUrl,
				publicPath,
				buildFolder,
				useYarn
			);
		},
		(err) => {
			const tscCompileOnError =
				process.env.TSC_COMPILE_ON_ERROR === "true";
			if (tscCompileOnError) {
				console.log(
					chalk.yellow(
						"编译过程中发生下列错误 (在你部署自己的项目之前，你会需要校验这些信息):\n"
					)
				);
				printBuildError(err);
			} else {
				console.log(chalk.red("信息对比失败.\n"));
				printBuildError(err);
				process.exit(1);
			}
		}
	)
	.catch((err) => {
		if (err && err.message) {
			console.log(err.message);
		}
		process.exit(1);
	});

// Create the production build and print the deployment instructions.
function build(previousFileSizes) {
	console.log("正在进行真实线上环境的编译打包...");
	const compiler = webpack(config);
	return new Promise((resolve, reject) => {
		compiler.run((err, stats) => {
			let messages;
			if (err) {
				if (!err.message) {
					return reject(err);
				}

				let errMessage = err.message;

				// Add additional information for postcss errors
				if (Object.prototype.hasOwnProperty.call(err, "postcssNode")) {
					errMessage +=
						"\n编译错误: Begins at CSS selector " +
						err["postcssNode"].selector;
				}

				messages = formatWebpackMessages({
					errors: [errMessage],
					warnings: [],
				});
			} else {
				messages = formatWebpackMessages(
					stats.toJson({ all: false, warnings: true, errors: true })
				);
			}
			if (messages.errors.length) {
				// Only keep the first error. Others are often indicative
				// of the same problem, but confuse the reader with noise.
				if (messages.errors.length > 1) {
					messages.errors.length = 1;
				}
				return reject(new Error(messages.errors.join("\n\n")));
			}
			if (
				process.env.CI &&
				(typeof process.env.CI !== "string" ||
					process.env.CI.toLowerCase() !== "false") &&
				messages.warnings.length
			) {
				console.log(
					chalk.yellow(
						"\nTreating warnings as errors because process.env.CI = true.\n" +
							"Most CI servers set it automatically.\n"
					)
				);
				return reject(new Error(messages.warnings.join("\n\n")));
			}

			const resolveArgs = {
				stats,
				previousFileSizes,
				warnings: messages.warnings,
			};

			if (writeStatsJson) {
				return bfj
					.write(
						paths.appBuild + "/bundle-stats.json",
						stats.toJson()
					)
					.then(() => resolve(resolveArgs))
					.catch((error) => reject(new Error(error)));
			}

			return resolve(resolveArgs);
		});
	});
}

function copyPublicFolder() {
	fs.copySync(paths.appPublic, paths.appBuild, {
		dereference: true,
		filter: (file) => file !== paths.appHtml,
	});
}
